Eyepiece for virtual, augmented, or mixed reality systems

Abstract

An eyepiece waveguide for an augmented reality. The eyepiece waveguide can include a transparent substrate with an input coupler region, first and second orthogonal pupil expander (OPE) regions, and an exit pupil expander (EPE) region. The input coupler region can be positioned between the first and second OPE regions and can divide and re-direct an input light beam that is externally incident on the input coupler region into first and second guided light beams that propagate inside the substrate, with the first guided beam being directed toward the first OPE region and the second guided beam being directed toward the second OPE region. The first and second OPE regions can respectively divide the first and second guided beams into a plurality of replicated, spaced-apart beams. The EPE region can re-direct the replicated beams from both the first and second OPE regions such that they exit the substrate.

What is claimed is: 
     
       1. An eyepiece waveguide for a virtual reality, augmented reality, or mixed reality system, the eyepiece waveguide comprising:
 a substrate that is at least partially transparent; 
 an input coupler region formed on or in the substrate and comprising diffractive optical features configured to divide and re-direct at least one input light beam that is externally incident on the input coupler region into first and second guided light beams that propagate inside the substrate; 
 a first orthogonal pupil expander (OPE) region formed on or in the substrate and configured to divide the first guided light beam from the input coupler region into a plurality of parallel, spaced-apart light beams; 
 a second OPE region formed on or in the substrate and configured to divide the second guided light beam from the input coupler region into a plurality of parallel, spaced-apart light beams; and 
 a common exit pupil expander (EPE) region formed on or in the substrate and configured to re-direct the light beams from both the first and second OPE regions such that they exit the substrate, 
 wherein the input coupler region is positioned between the first OPE region and the second OPE region and is configured to direct the first guided light beam toward the first OPE region and to direct the second guided light beam toward the second OPE region, and 
 wherein the diffractive optical features of the input coupler region comprise a plurality of features laid out in a hexagonal lattice pattern. 
 
     
     
       2. The eyepiece waveguide of  claim 1 , wherein the substrate is less than 325 microns thick. 
     
     
       3. The eyepiece waveguide of  claim 1 , wherein the substrate comprises glass, plastic, or polycarbonate. 
     
     
       4. The eyepiece waveguide of  claim 1 , wherein the eyepiece waveguide is configured to project a color component of image data. 
     
     
       5. The eyepiece waveguide of  claim 1 , further comprising a projector to direct light toward the input coupler region. 
     
     
       6. The eyepiece waveguide of  claim 1 , wherein the input coupler region is configured to separate the input light beam into a +1 diffractive order directed toward the first OPE region and a −1 diffractive order directed toward the second OPE region. 
     
     
       7. The eyepiece waveguide of  claim 1 , wherein the first and second OPE regions are separated by approximately 180° and the EPE region is located at about 90° to both OPE regions. 
     
     
       8. The eyepiece waveguide of  claim 1 , wherein the first and second OPE regions are slanted toward the EPE region. 
     
     
       9. The eyepiece waveguide of  claim 8 , wherein the first and second OPE regions are separated by approximately 120° and the EPE region is located at about 60° to both OPE regions. 
     
     
       10. The eyepiece waveguide of  claim 1 , wherein the diffractive optical features of the input coupler region comprise a crossed grating. 
     
     
       11. The eyepiece waveguide of  claim 1 , wherein the diffractive optical features of the input coupler region are configured to direct light toward the first and second OPE regions, and toward the EPE region without first passing through either of the OPE regions. 
     
     
       12. The eyepiece waveguide of  claim 1 , wherein the first and second OPE regions comprise diffractive optical features to divide each of the first and second guided light beams into the plurality of parallel, spaced-apart light beams. 
     
     
       13. The eyepiece waveguide of  claim 12 , wherein the diffractive optical features of the first and second OPE regions comprise a plurality of lines forming diffraction gratings. 
     
     
       14. The eyepiece waveguide of  claim 13 , wherein the diffraction gratings of the first and second OPE regions are angled so as to direct the plurality of spaced-apart light beams toward the EPE region. 
     
     
       15. The eyepiece waveguide of  claim 1 , further comprising:
 a first spreader region that receives the light beams from the first OPE region and spreads their distribution so as to reach a larger portion of the EPE region; and 
 a second spreader region that receives the light beams from the second OPE region and spreads their distribution so as to reach a larger portion of the EPE region. 
 
     
     
       16. The eyepiece waveguide of  claim 15 , wherein the first spreader region and the second spreader region are both configured to spread the distribution of the light beams toward the center of the EPE region. 
     
     
       17. The eyepiece waveguide of  claim 15 , wherein the first and second spreader regions comprise diffractive optical features. 
     
     
       18. The eyepiece waveguide of  claim 17 , wherein the diffractive optical features of each of the first and second spreader regions comprise a plurality of lines that form diffraction gratings. 
     
     
       19. The eyepiece waveguide of  claim 18 , wherein the diffraction grating of the first spreader region is oriented at approximately 90° to a diffraction grating of the first OPE region, and wherein the diffraction grating of the second spreader region is oriented at approximately 90° to a diffraction grating of the second OPE region.